Touch screens are usually integrated in liquid crystal display panels, to form a variety of electronic products, such as mobile phones, laptops, MP3/MP4, etc. In order to improve a user experience with display devices, the display devices have been integrated extensively with touch screens.
The touch screens include touch electrodes used to sense touch positions. In conventional solutions, since a touch layer is a common electrode layer, the common electrode layer is patterned to form a number of common electrode plates insulated from each other. Each of the common electrode plates is electrically connected with sensing electrode wires through vias. The sensing electrode wires are used as leading wires to electrically connect the common electrode plates with a touch display chip. Conventional touch electrodes are formed of indium tin oxides (ITO), but the ITO has relatively poor conductive properties, thereby increasing resist and load delay of the common electrode plates, resulting in poor touch performance of the touch screens.
As shown in FIG. 1, an in-cell touch screen of the conventional technologies includes a substrate 101, a buffer layer 102 disposed on a surface of the substrate 101, a gate insulating layer 103 disposed on a surface of the buffer layer 102, an interlayer insulating layer 104 disposed on a surface of the gate insulating layer 103, a first planarization layer 105 disposed on a surface of the interlayer insulating layer 104, a common electrode layer 106 disposed on a surface of the first planarization layer 105, a dielectric layer 107 disposed on a surface of the common electrode layer 106, sensing electrode wires 110 disposed on a surface of the dielectric layer 107, a passivation layer 108 disposed on the surface of the dielectric layer 107, and a pixel electrode 109 disposed on a surface of the passivation layer 108.
The sensing electrode wires 110 are electrically connected with the common electrode layer 106 through vias 111 in the dielectric layer 107. The pixel electrode 109 is electrically connected with a drain electrode 112 of a thin film transistor through vias 113, and the vias 113 pass through the passivation layer 108, the dielectric layer 107, the common electrode layer 106, and the first planarization layer 105 in sequence.
As shown in FIG. 2, an in-cell touch screen of the conventional technologies includes a planarization layer 201. A common electrode layer is disposed on a surface of the planarization layer 201, wherein a patterning process is performed on the common electrode layer to form a number of common electrode plates 202 insulated from each other. Each of the common electrode plates 202 is electrically connected with a sensing electrode wire 203, and another end of the sensing electrode wire 203 is connected with a touch display chip 204.
As mentioned above, since the common electrode plates, used as the touch electrodes, of in-cell touch screens in conventional technologies have poor conductive properties, touch signal delay is increased or decreased thereby resulting in poor touch performance of the touch screens.